Perimidene and benzimidazole derivatives useful in curable compositions

ABSTRACT

A compound prepared by reacting at least one aromatic or aliphatic polyamine compound having at least two amine groups, which are separated by no more than one carbon atom, with at least one carbonyl-containing compound selected from the group consisting of aldehydes and ketones, wherein said polyamine compound is selected from: 
     aliphatic polyamines having 2-20 carbon atoms corresponding to the formula: ##STR1##  wherein A is a direct carbon-carbon bond or --CH 2  -- and R 3  and R 4  are independently hydrogen or alkyl which may be branched or unbranched and which may be unsubstituted or substituted with amine groups; 
      wherein said aldehydes correspond to the formula: ##STR2##  wherein R represents alkyl of 1-20 carbon atoms, which may be branched or unbranched, and which may be unsubstituted or substituted with --CHO or --COOH; --CHO; --COOH; or phenyl which may be unsubstituted or substituted with --CHO, --OH OR lower alkoxy of 1-5 carbon atoms, and wherein said ketones correspond to the formula: ##STR3##  wherein R 1  and R 2  independently represent alkyl of 1-20 carbon atoms, which may be branched or unbranched, and whose chain may be interrupted by one or more ##STR4##  groups; phenyl; or R 1  or R 2  may together form a cycloaliphatic ring which may be interrupted by a ##STR5##  group; or R 1  and R 2  may together form an O-heterocyclic ring which may be substituted with lower alkyl of 1-5 carbon atoms, --OH or acetyl; curable compositions containing the same; a method of curing; and composite articles are disclosed.

This is a continuation of application Ser. No. 286,897, filed July 27,1981, now U.S. Pat. No. 4,427,802.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to heterocyclic multifunctional amine adducts,methods of preparing the same, curable compositions containing the sameand methods of curing the same.

2. Description of the Prior Art

Polymerized resins are employed for many commercial and militaryapplications. These compositions provide lightweight products which havea high strength to weight ratio and good durability. Polymerizedcompositions are employed for many end uses which include moldingcompounds, adhesives, laminates made by bonding layers of impregnatedreinforcement together and other such molded products. Particularlyimportant is the use of polymerized epoxy resin in combination withreinforcements for aircraft and aerospace applications. These specificarticles generally require very smooth surfaces combined with hightemperature strength and resistance to stress fatigue. Applicationsinclude aircraft tail assemblies, leading edges and fairings.Polyepoxides, phenolics, isocyanates and bismaleimides representexamples of polymers which are cured by combining them with catalysts orhardeners to yield cured or cross-linked compositions. Typical hardenersor cross-linking agents which cure epoxy prepolymers are aliphatic andaromatic polyamines. Smith et al, U.S. Pat. No. 3,032,526, discloses thecuring of a glycidyl polyether of a dihydric phenol with the reactionproduct of m-phenylenediamine and a dialkyl ketone. Ramos, U.S. Pat. No.3,398,211, discloses synthetic resins derived from diglycidylethers ofpolyhydric alcohols interacting with diamines or hydroquinones and1,4-cyclohexadiene dioxide. Labana et al, U.S. Pat. No. 3,714,120,discloses accelerators which are used to catalyze the curing ofbisphenol A-epoxy type resins by aromatic diamines. Montesano, U.S. Pat.No. 3,316,191, discloses the curing of epoxy resins with tertiary aminesin the presence of converters such as dodecenyl succinic anhydride.Kehr, U.S. Pat. No. 3,171,830, discloses a cross-linking process forsolid olefin polymers containing carbonyl groups by subjecting saidpolymers to the action of hydrazine or a polyamine compound. Suzuki etal, U.S. Pat. No. 3,950,451, discloses a hardenable composition of anepoxy compound and a hardener produced by coupling a phenol, a diamine,formaldehyde or a functional derivative thereof and an alkylphenol.Current technology uses diamino diphenyl sulfone which is commonlyreferred to as DDS for curing epoxy resins to yield good mechanicalproperties of the cured part at elevated temperatures, e.g., ChemicalAbstracts 89: 44579 m (Aponyi et al, Natl. SAMPE Symp. Exhib. 1978, 23,479-89). However, sulfones, in general, result in a cross-linkedcomposition which has poor wet strength after being subjected to a wetor high humidity water environment.

Also, the cured compositions utilizing sulfones as the crosslinkingagent have brittle failure characteristics or what is commonly describedas a lack of toughness. This problem has been overcome to some extent bythe addition of plasticizers, flexibilizers or elastomers which whenadmixed with the polymerizing resin increase fatigue resistance orbrittle failure to some degree. These additives when used in combinationwith DDS cross-linking agent and aN,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl methane represent thecurrent state of the art. A need therefore continues to exist forcurative agents which will yield materials having excellent physical andmechanical properties.

SUMMARY OF THE INVENTION

Accordingly, one object of the invention is to provide a curative agentwhich will produce curable compositions having excellent physical andmechanical properties.

Another object of the invention is to provide curable compositionshaving excellent physical and mechanical properties.

Another object of the invention is to provide a process for curing suchcompositions.

A further object of this invention is to provide curable compositionswhich can be used in conjunction with fillers, reinforcements andextenders to yield a composite structure.

Briefly, these objects and other objects of the invention as hereinafterwill become more readily apparent can be attained by providing acurative agent comprising a novel heterocyclic multifunctional amineadduct prepared by reacting at least one aromatic or aliphatic polyaminecompound having at least two amine groups, which are separated by nomore than one carbon atom, with at least one carbonyl-containingcompound selected from the group consisting of aldehydes and ketones.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is common knowledge that amines react with ketones to form Schiff'sbases or ketamines, e.g., ##STR6## It is also know that1,8-diamino-naphthalene will react with carboxylic acids and esters, inthe present of an oxidizing agent to yield perimidines,Balasubramaniyan, Chem. Revs., 66, 6, pp 567.

The novel heterocyclic multifunctional amine adduct of the presentinvention is the reaction product of at least one aromatic or aliphaticpolyamine compound having at least two amine groups, which are separatedby no more than one carbon atom, with at least one carbonyl-containingcompound selected from the group consisting of aldehydes and ketones.Suitable aldehydes correspond to the formula: ##STR7## wherein Rrepresents:

an alkyl group of one to twenty carbon atoms, which may be branched orunbranched, and which may be unsubstituted or substituted with analdehyde group (--CHO) or a carboxyl group (--COOH); an aromaticresidue, preferably a phenyl group, which may be unsubstituted orsubstituted with an aldehyde group, a hydroxyl group or a lower alkoxygroup of one to five carbon atoms. Examples of such aldehydes areterephtalaldehyde, glyoxal, glutaraldehyde, glyoxylic acid,salicylaldehyde, vanillin and o-vanillin and heptaldehyde

Suitable ketones correspond to the formula: ##STR8## wherein R₁ and R₂independently represent:

an alkyl group of one to twenty carbon atoms, which may be branched orunbranched, whose chain may be interrupted by one or more carbonylgroups ##STR9##

an aromatic residue, preferably phenyl; or

R₁ and R₂ may together form a cycloaliphatic ring may be interrupted bya carbonyl group; or R₁ and R₂ may together form an O-heterocyclic ringwhich may be substituted with lower alkyl group of one to five carbonatoms, hydroxyl group or acetyl group.

Examples of such ketones are 2,4-pentanedione; 2,3-butanedione; benzil;1,3-cyclohexanedione; acetone; 2-butanone; 2-heptanone; dehydroaceticacid and acetophenone.

Suitable polyamines are selected from: aliphatic polyamines having twoto twenty carbon atoms corresponding to the formula: ##STR10## wherein Ais a direct carbon-carbon bond or a --CH₂ -- group and R₃ and R₄ areindependently hydrogen, alkyl groups which may be branched or unbranchedand which may be unsubstituted or substituted with amine groups (--NH₂);##STR11## Examples of such polyamines are 1,3-diamino-propane;1,2-diamino-benzene; 1,2,4,5-tetra amino-benzene;3,3',4,4'-tetramino-diphenylmethane; 1,8-diamino-naphthalene and1,4,5,8-tetra amino-naphthalene.

The heterocyclic diamine adducts of this invention may be prepared byreacting the aromatic or aliphatic polyamine compound having at leasttwo amine groups, which are separated by no more than one carbon atom,with at least one carbonyl-containing compound selected from the groupconsisting of aldehydes and ketones at a temperature between roomtemperature and about 250° F., for convenience higher temperatures arepreferred for increased speed of reaction, most preferably, at refluxtemperature of the particular reaction mixture.

Any inert solvent, which will dissolve the reaction components can beused, for examples, alcohols such as ethanol or conventional industrialsolvents such as methyl cellusolve. Additionally, thecarbonyl-containing compound, the aldehyde or ketone, may be used as asolvent. Alternatively, no solvent can be used, however, it is desirableto maintain the carbonyl to diamine molar ratio at 1:1 or in slightexcess so as to ensure completion of reaction.

A catalyst may be present so as to increase the reaction rate. Any acidmay be used, e.g. mineral acids such as hydrochloric acid or sulfuricacid and organic acids such as benzene disulfonic acid orp-toluenesulfonic acid.

The heterocyclic diamine adduct may be recovered from the reactionmixture by cooling the same and recovering the precipitated product andthen washing and/or drying the same. Alternatively, the reaction mixturemay be drowned in water, the precipitated reaction product recovered byfiltration and then washing and drying the precipitate. Advantageously,the hetrocyclic diamine adduct may be produced as a solution by using alarge excess of carbonyl-containing compound during the reaction or byadding excess carbonyl-containing compound upon completion of thereaction.

Mixtures of polyamine compounds, mixtures of aldehydes, mixtures ofketones and/or mixtures of aldehydes and ketones may be used in thereaction to advantageously vary the properties of the heterocyclicdiamine adduct.

Suitable compounds prepared by the above-noted technique include thosecorresponding to the formula: ##STR12## wherein R₅ and R₆ areindependently selected from the group consisting of hydrogen, alkyl,phenyl, ##STR13## and R₅ and R₆ may jointly form ##STR14## and R₇ isselected from the group consisting of: ##STR15## Particularly preferreddiamine adducts are produced from 1,8-diamino-naphthalene and1,3-diamino-propane.

The novel heterocyclic diamine adducts of this invention find particularuse as curative agents in curable resin compositions. In particular, anyresin reactive with an active hydrogen atom can be cured by the noveldiamine adducts. Illustrative of such resins are the epoxy resins,phenolics, bismaleimide resins, isocyanates. Of particular importanceare the epoxy resins.

Epoxy resins are compounds which contain an oxygen atom connected to twoadjacent carbon atoms. A variety of epoxy resins are known andcommercially available. Among the important groups of epoxy resins arethose based on bisphenol A (4,4'-isopropylidine diphenol) andepichlorohydrin, novolacs and epichlorohydrin, aliphatic diepoxy ethers,aliphatic diepoxy esters, cycloaliphatic diepoxides, and 4,4'-methanedianiline and epichlorohydrin.

Epoxy resins of the type of diglycidyl ethers of bisphenol A are mosteasily available under trade names of Epon 828, Epon 1001, Epon 1002,Epon 1004, Epon 1007 from Shell Chemical Co. They are also availablefrom Dow Chemical Co. with DER 331 as an example, or from Ciba ProductsCo. with Araldite 6010 as an example, or Celanese Epi Rez with Epi Rez510 as an example. Their chemical structure corresponds to the formula:##STR16## wherein n is the degree of the polymerization.

Novalac type epoxy resins are obtained by reacting novolacs, which arereaction products of phenol and formaldehyde, with epichlorohydrin andcorrespond to the general formula: ##STR17## wherein R is ##STR18## andn is the degree of polymerization. Cresol may be substituted in place ofphenol to form the corresponding novolacs, of which an example is theECN series from Ciba.

Aliphatic ether type epoxy resins are of the general formula: ##STR19##wherein R is a divalent alkyl group. While the formula shows two epoxygroups present, epoxy resins with more or less than two epoxy groups permolecule are also useful. An example of aliphatic ester type epoxy resinis diglycidyl adipate.

Cycloaliphatic type epoxy resins are those which contain oxygen atomattached to two adjacent carbon atoms which are part of ring containingother carbon, nitrogen and sulfur atoms. Examples of cycloaliphatic typeepoxy resins are bis (2,3-epoxycyclohexanol) adipate and bis(2,3-epoxycyclopentyl) ether. A commercially available cycloaliphaticepoxy resin CY 178 from Ciba Products Co. is bis (2,3 epoxy -4-methylcyclohexanol) adipate.

An epoxy resin of the type of tetraglycidyl methane diamiline isavailable from Ciba Geigy under the trade name MY 720 and corresponds tothe formula: ##STR20## This resin is particularly preferred as it formsthe basis of curable compositions of great utility in the aircraft andaerospace industry, e.g., structural composites of glass or graphitefibers.

Epoxy resins can also be prepared by copolymerization of unsaturatedepoxy compounds such as glycidyl methacrylate with other vinyl monomers.The copolymerization conditions can be controlled to obtain polymers ofwidely different molecular weight, e.g., 2,000 to 100,000. Such vinylpolymerization techniques are well-known and conventional. The epoxycontent of the copolymers can be controlled by using an appropriateamount of vinyl epoxy monomer, e.g., glycidyl methacrylate, relative tothe amount of other monomer or monomers used.

The curable compositions of the present invention comprise a resinreactive with an active hydrogen atom, e.g., an epoxy resin, and theheterocyclic mutifunctional amine adduct of this invention. Theheterocyclic multifunctional amine adduct can be used in any amount inthe curable composition, however, it is preferred to have a ratio ofhydrogen equivalents of the adduct to reactive sites of the resin of0.1-1.0, most preferably, the stoichiometric ratio or slightlythereunder. Additionally, mixtures of heterocyclic diamine adducts canbe used as well as mixtures of resins, bearing in mind the desiredstoichiometric ratio of active hydrogens and reactive sites.

Other ingredients may be included in the curable composition toadvantageously influence the properties thereof.

A surfactant may be added, in amounts conventional in the art, to reducethe surface tension of the mixture. Illustrative of such surfactants arethe siloxane-oxyalkylene block copolymers and vinyl silaneoxyalkylenegraft copolymers and Triton X100 (Rohm & Haas -an octylphenoxypolyethoxyphenol surfactant).

A thixotropic agent may be added, in amounts conventional in the art, tocontrol composition viscosity. The thixotropes may also function asfillers or extenders. Illustrative of such materials are mica, calciumcarbonate, calcium phosphate, silica, glass, metal oxides, cellulose,starch, clays and diatomaceous earth.

Suitable catalysts may also be added, in conventional amounts, toprovide a controlled and predictable composition cure rate. Catalystscan be from the family of latent hardeners such as boron trihalidecomplexes and dicyandiamide.

In addition, flexibilizing agents or elastomeric compounds, which mayprecipitate out as a second phase, may be incorporated into thecomposition to impart viscosity control along with producing increasedtoughness in the cured composition and thus inhibit fatigue and crackpropagation. Illustrative of such flexibilizers or elastomers areacrylonitrile-butadiene copolymers, urethane elastomers andthermoplastic polymers, in general.

Alternatively, rather than use the heterocyclic diamine adduct, per se,in formulating the composition, it is possible to prepare the samein-situ by addition of the appropriate amounts of polyamine componentand carbonyl-containing component. In this case, it is preferable toinclude an acid catalyst, as noted above, in the composition so as toreduce the reaction time necessary to form the heterocyclic diamineadduct.

It is also possible to incorporate the heterocyclic diamine adduct as aprepolymer, e.g., as the reaction product of the diamine adduct and abismaleimide.

Curing of the composition is achieved by exposing the composition tosufficient energy to cause curing or cross-linking. The energy sourcemay be heat or high energy radition such as microwave radiation.Typically, the composition is brought to a temperature of 350° F. orhigher for 1 hour or more. Conventional post-cure treatments are alsoapplicable to the composition of this invention.

Prior to curing or cross-linking, the curable composition can be appliedto a reinforcing material. Such reinforcing materials may be in the formof woven, knitted or unidirectional parallel threads; filaments; yarns;or unwoven fibers made from either continuous or staple fibers. Thesereinforcements can be of organic or inorganic origin. Illustrative ofsuch reinforcements are cotton, paper, fiberglass, polyesters,polyaramids, polyolefins, graphite, ceramics, metals and metalderivatives. Such reinforced compositions can be assembled as laminae toform a composite article which is subsequently cured. The resincomposition can be applied to such reinforcements by techniquesconventional in the art such as inpregnation, curtain coating, doctoringhot metal extrusion or callendering.

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples which are providedherein for purposes of illustration only and are not intended to belimiting unless otherwise specified.

EXAMPLE 1 Product of 1,8-diamino-naphthalene and methyyl ethyl ketone##STR21##

Into a flask, equipped with a stirrer, reflux condenser, thermometerwell and addition port, is placed 152.8 grams (about a 6% excess) ofmethyl ethyl ketone and 0.8 gram of p-toluenesulfonic acid. The solutionis stirred and 158.2 grams of 1,8-diamino-naphthalene is added over 30minutes with sufficient cooling to allow the temperature to reach reflux(176° F.) at the end of the addition. The solution is then refluxed anadditional 30 minutes. The yield is essentially guantitative. Thereaction product may be isolated neat by evaporating off the excessmethyl ethyl ketone and water, or it may be diluted further with acetoneor more methyl ethyl ketone, mixed with other ingredients and used in asolvent coating application.

EXAMPLE 2 Reaction product of 1,8-diamino-naphthalene andterephthalaldehyde ##STR22##

Into a beaker equipped with a stirrer and thermometer is placed 1000 mlof methyl cellusolve, 84.8 grams of terephthalaldehyde and 200 grams of1,8-diaminonaphthalene. The mixture is heated and stirred to about 175°F. where a solution occurs. Then 0.4 gram of p-toluenesulfonic acid isadded and stirring and heating are continued at 200°-240° F. for 11/2hours during which time the product precipitates out. The mixture iscooled, drowned into 3-4 times the volume of water, collected and driedin a 230° F. oven. The recovery is 244 gram (93% yield).

EXAMPLE 3 Reaction product of 2,4-pentanedione and1,8-diamino-naphthalene ##STR23##

Into a flash, equipped with a stirrer, reflux condenser, thermometerwell and addition port, is placed 66.7 grams 2,4-pentanedione and 1.0gram of p-toluenesulfonic acid. 200 grams 1,8-diamino-naphthalene areadded and the mixture is refluxed (pot temperature about 100° C.) andstirred for 21/2 hours. It is then poured hot into trays and driedovernight at 230° F. to remove water and excess dione. The yield isessentially quantitative.

EXAMPLE 4 Reaction product of acetone and 1,3-diamino-propane ##STR24##

Into a flask, equipped with a stirrer, reflux condenser and additionport, is placed 58.1 grams of acetone and 0.3 gram of p-toluenesulfonicacid. 74.1 grams of 1,3-diamino-propane is added over 20 minutes withsufficient cooling such that the solution is at reflux (about 106°) atthe end of the addition. The solution is refluxed an additional 11/2hours. The yield is essentially quantitative. Water contained in theproduct may be removed by distillation, if necessary.

EXAMPLE 5 Reaction product of 1,2-diamino-benzene and acetone ##STR25##

600 ml of acetone, 1 gram of paratoluenesulfonic acid and 200 grams of1,2-diamino-benzene are stirred at reflux for 4 hours, cooled, drownedin 2500 ml of water, and the solid is collected and dried in a 180° F.oven. The yield is essentially quantitative.

EXAMPLES 6-21

In a similar manner, the following reaction products were prepared fromthe indicated components.

    __________________________________________________________________________    Example                        Carbonyl-                                      No.  Reaction Product          Containing Component                                                                        Diamine Component                __________________________________________________________________________          ##STR26##                                                                                               ##STR27##                                                                                   ##STR28##                       7                                                                                   ##STR29##                                                                                               ##STR30##                                                                                   ##STR31##                       8                                                                                   ##STR32##                                                                                               ##STR33##                                                                                   ##STR34##                       9                                                                                   ##STR35##                                                                                               ##STR36##                                                                                   ##STR37##                       10                                                                                  ##STR38##                                                                                               ##STR39##                                                                                   ##STR40##                       11                                                                                  ##STR41##                                                                                               ##STR42##                                                                                   ##STR43##                       12                                                                                  ##STR44##                                                                                               ##STR45##                                                                                   ##STR46##                       13                                                                                  ##STR47##                                                                                               ##STR48##                                                                                   ##STR49##                       14                                                                                  ##STR50##                                                                                               ##STR51##                                                                                   ##STR52##                       15                                                                                  ##STR53##                                                                                               ##STR54##                                                                                   ##STR55##                       16                                                                                  ##STR56##                                                                                               ##STR57##                                                                                   ##STR58##                       17                                                                                  ##STR59##                                                                                               ##STR60##                                                                                   ##STR61##                       18                                                                                  ##STR62##                                                                                               ##STR63##                                                                                   ##STR64##                       19                                                                                  ##STR65##                                                                                               ##STR66##                                                                                   ##STR67##                       20                                                                                  ##STR68##                                                                                               ##STR69##                                                                                   ##STR70##                       21                                                                                  ##STR71##                                                                                               ##STR72##    H.sub.2 N(CH.sub.2).sub.3NH.s                                                 ub.2 1,3-Diamino-propane         __________________________________________________________________________

EXAMPLE 22 Hot meltable resin system

66 grams of MY 720 (N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, made by Ciba Geigy Corp.) is heated to about 140° F. and 38.6grams of the reaction product produced according to Example 3 is mixedin thoroughly by stirring. The mixture is cooled to below 120° F. and 1gram of dicyandiamide (product of American Cyanamid) is mixed in. Themixture is roller milled and the resulting hot meltable resin systemwhich is 100% solids (contains no volatiles) is coated on 7781 stylewoven glass, by conventional techniques, made into a 10 ply laminate andvacuum bag autoclave cured for 11/2 hours at 350° F. by conventionaltechniques. No post cure was given. The following were the properties ofthe laminate:

    ______________________________________                                        Thickness:         92 mils                                                    350° F. Flexure Strength:                                                                 76.4 ksi                                                   350° F. Flexure Modulus:                                                                  3.52 × 10.sup.6 psi                                  350° F. Short Beam Shear                                                                  6.84 ksi                                                   Voids:             void free                                                  350° F. Flexure Strength:                                                                 52.5 ksi                                                   (after 96 hr. water boil)                                                     350° F. Flexure Modulus:                                                                  2.79 × 10.sup.6 psi                                  (after 96 hr. water boil)                                                     350° F. Short Beam Shear:                                                                 3.45 ksi                                                   (after 96 hr. water boil)                                                     ______________________________________                                    

The uncured preimpregnated material had good initial tack and drape andretained it for at least 10 days storage at room temperature.

EXAMPLE 23 Solution coated resin system

16 grams of the reaction product, according to Example 1, is made byheating 11.9 grams of 1,8-diaminonaphthalene, 0.06 gram ofp-toluenesulfonic acid and 339 grams of methyl ethyl ketone at nearreflux for 30 minutes. The solution is cooled to under 140° F. and thefollowing are added with stirring:

    ______________________________________                                        172    grams    MY 720 (Ciba Geigy)                                           46     grams    diglycidyl aniline (Mobay)                                    120             reaction product of Example 2                                 2      grams    dicyandiamide (American Cyanamide)                            3      grams    1001 CG (B. F. Goodrich, copolymer                                            of butadiene and acrylonitrile,                                               previously dissolved 15% by wt. in                                            methyl ethyl ketone)                                          ______________________________________                                    

The mixture is ball milled 2 hours, and results in a resin mixture ofabout 50% solids. 7781 style woven glass and Thornel T300 3K 121/2 by121/2 square weave woven graphite cloth strips are solution coated withthis resin using coventional techniques and the solvent is flashed offfor 10 minutes at 190° F. in a circulating air oven. The resin pick-upis about 35% and 37%, respectively. These are made into laminates andvacuum bag autoclave cured for 11/2 hrs. at 350° F. using standardindustry methods. No post cure was given. The following were theproperties of the laminate:

    ______________________________________                                                                    Woven                                                               7781 Glass                                                                              Graphite                                          ______________________________________                                        # of plies          10          13                                            Thickness (mils)    92          105                                           350° F. Flexure Strength (ksi)                                                             76          65                                            350° F. Flexure Modulus (×10.sup.6 psi)                                              3.7         7.5                                           350° F. Short Beam Shear (ksi)                                                             6.25        5.5                                           Voids               Void Free   Void                                                                          Free                                          350° F. Flexure Strength (ksi)                                                             56          37                                            after 96 hr. water boil                                                       350° F. Flexure Modulus (×10.sup.6 psi)                                              3.25        6.8                                           after 96 hr. water boil                                                       350° F. Short Beam Shear (ksi)                                                             4.2         3.55                                          after 96 hr. water boil                                                       ______________________________________                                    

The uncured preimpregnated material had good initial tack and drape andretained it for at least 10 days storage at room temperature.

EXAMPLE 24 Hot meltable resin system

This is the same resin system in Example 23, only a hot meltable versionthereof, i.e. 100% solids --no volatiles. Warm together to about 140°F.:

    ______________________________________                                        MY 720                145 grams                                               Diglycidyl aniline     46 grams                                               My 720/1001 mix*       30 grams                                               ______________________________________                                         (*made by dissolving 1 part 1001 CG (15% solution in methylethylketone) i     9 parts MY 720 and evaporating off the solvent)                          

and mix in:

    ______________________________________                                        Reaction product of Example 2                                                                         120 grams                                             Reaction product (neat) of                                                                             16 grams                                             Example 1                                                                     Dicyandiamide            2 grams                                              ______________________________________                                    

and roller milled. This resin is hot melted, using conventionaltechniques, on to Thornel T300 3K graphite fibers with an aerial weightof 145 gm/m² to form a unidirectional preimpregnated material of about33% net resin content. A 10 ply 0 degree unidirectional laminate wasmade and vacuum bag autoclave cured for 11/2 hours at 350° F., byconventional techniques, which had the following properties:

    ______________________________________                                        Thickness (mils)      72                                                      350° F. Flexure Strength (ksi)                                                               160                                                     350° F. Flexure Modulus (×10.sup.6 psi)                                                17.9                                                    350° F. Short Beam Shear (ksi)                                                               8.1                                                     Voids                 Void Free                                               ______________________________________                                    

The uncured preimpregnated material had good initial tack and drape andretained it for at least 10 days storage at room temperature.

EXAMPLE 25 Hot meltable resin system using a prepolymer

8.2 grams of ##STR73## that is, the reaction product of1,8-diamino-naphthalene with acetone, produced by the same procedure asin Example 1 only substituting acetone in place of methylethylketone,30.5 grams of ERL 4206 (a cycloaliphatic epoxy made by Union Carbide),and 41.2 grams of 4,4'-bismaleimidodiplenylmethane are stirred andheated at 260° F. for 20 minutes. A linear prepolymer is formed from themaleimide and the reaction product of the 1,8-diaminonaphthalene withacetone and the reaction progress is monitored by High Pressure LiquidChromatography as the reaction product peak disappears. The resin iscooled to about 150° F. and 20 grams of additional4,4'-bismaleimidodiphenylmethane and 8 grams of the reaction productaccording to Example 2 were mixed in, followed by 0.4 gram of dicumylperoxide at under 120° F. The mixture was roller milled thoroughly. Thisresin was hot melt coated on to 7781 style woven glass and Thornel T3003K 121/2by 121/2 square weave woven graphite, made into laminates, givena 2 hr., 375° F. vacuum bag autoclave cure, using conventionaltechniques, followed by a free standing 16 hr, 500° F. post cure for thewoven graphite laminate and a 4 hr, 475° F. post cure for the glasslaminate. The following were the laminate properties:

    ______________________________________                                                                   Woven                                                                7781 Glass                                                                             Graphite                                           ______________________________________                                        # plies             10         13                                             Thickness (mils)    92         82                                             500° F. Flexure Strength (ksi)                                                             52         53                                             500° F. Flexure Modulus (×10.sup.6 psi)                                              3.12       8.3                                            500° F. Short Beam Shear (ksi)                                                             3.75       4.1                                            Voids               Void Free  Void Free                                      ______________________________________                                    

Heat age 100 hr. @475° F., then:

    ______________________________________                                                             Woven Graphite                                           ______________________________________                                        500° F. Flexure Strength (ksi)                                                                54     (1.6%                                                                         wt. loss)                                       500° F. Flexure Modulus (×10.sup.6 psi)                                                 8.8                                                    500° F. Short Beam Shear (psi)                                                                4.0                                                    ______________________________________                                    

Having now fully described this invention, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit or scope of the inventionset forth herein.

What is claimed as new and desired to be covered by Letters Patentis:
 1. The compound having the formula: ##STR74##
 2. The compound havingthe formula: ##STR75##
 3. The compound having the formula: ##STR76## 4.The compound having the formula: ##STR77##
 5. The compound having theformula: ##STR78##
 6. The compound having the formula: ##STR79##